The invention relates to magnetic lift systems, and more particularly, it relates to increasing the total lift of a group of magnets by optimally spacing the magnets in a particular polarity arrangement.
Magnetic suspension of a high-speed vehicle is disclosed in U.S. Pat. No. 3,589,300, issued June 29, 1971, to Stefan L. Wipf, wherein the vehicle is propelled at a speed at which magnets that are carried by the vehicle are levitated along with the vehicle by repulsion of the magnets from mirror images resulting from eddy currents induced in a nonferromagnetic and continuous electrical conductor that defines a track for the moving vehicle. Each mirror image is, for practical purposes, directly opposite the magnet creating the image. A particular problem of magnetic lift systems, such as the Wipf system, for high-speed vehicles is the large weight-to-lift ratio of the magnets, particularly permanent magnets. For a practical magnetic lift system it is necessary to reduce the total weight to the point that a significant payload may be carried by the vehicle. One approach in maximizing the payload of a magnetically levitated vehicle utilizing permanent magnets opposite a nonferromagnetic and continuous conductor as a track is discussed by Richard K. Cooper, V. Kelvin Neil and Wayne R. Woodruff in Optimum Permanent-Magnet Dimensions for Repulsion Applications, IEEE Transactions on Magnetics, Vol. Mag.-9, No. 2, June 1973, pages 125-127. However, in both the Wipf patent and the Cooper et al paper, the magnetic lift discussed is primary lift, which is the lift only between each magnet and its directly opposite mirror image in a nonferromagnetic continuous electrically conductive track. Other publications regarding primary lift arrangements include a U.S. Pat. No. 3,470,828, issued Oct. 7, 1969, to J. R. Powell, Jr. et al, and U.S. Pat. No. 3,158,765 issued Nov. 24, 1964, to G. R. Polgreen. In the Powell patent a complex track consisting of a plurality of electrically conducting loops is disclosed, while in the Polgreen patent a complex track including long lines of permanent magnets is disclosed. However, in neither the Wipf Powell or Polgreen patents nor the Cooper et al paper, is there any discussion or recognition of a secondary lift effect. Any secondary lift effect of a high-speed vehicle that does not require added weight would provide a more favorable weight-to-lift ratio.